FIELD [Closed] IS PRESENT

Try it in the Notes Client to see if it gives you what you want.

Tried using this syntax and got a different error:

The field name used in the query cannot be found in the database.

The field Closed is in every document, and the database is full-text indexed.

I ran into this with a date field called CompletedDate which I set when the document was completed. But was blank otherwise. Domino does not like Blank Dates. So what I did was on creating the document I set the default value of CompletedDate to @TextToTime(@Text(@Time(1970;1;1;0;0;0);"S2") + " GMT") in a computed field on the Notes Form. Probably should do it as part of the XPage but .... it works. Now if I search for CompletedDate > Jan 1 1970 I get only those documents with an actual completeddate and if I search for completionDate < Jan 2 1970 I get the uncompleted documents. Takes a bit of fooling around to get it to work but then it works fine. Another problem with blank dates is if you have two or more replica of the Db on different servers. The date can get set correctly on server1 but when the document replicates to server2 it will not be typed as a date field but as a text field - a real mess. 

Here is a link to my question on StackOverFlow and some answers:

http://stackoverflow.com/questions/20578448/using-a-ftsearch-on-a-date-field

Thanks for the response.  Search queries using the IS PRESENT operator work on searches  with text fields but apparently not with date fields.  
I've come up with a work-around that also gives me the desired results.  I build separate Domino views for "Open" and "Closed" accounts, using view selection formulas:
 SELECT (Form="Accounts") & (!@IsNull(Closed))  for Closed and 
SELECT (Form="Accounts") & (@IsNull(Closed)) for Open
These formulas have no problem with empty date fields.
Then in the viewName property of the view panel, I select one or the other of these views, depending on the value of the sessionScope variable AcctsToDisplay.  (In addition, I have a third view displaying all documents, open and closed, for the case when AcctsToDisplay="All." )